Python and R are the industry standard at the moment, and you will find a lot of support on forums such as Stack Exchange for almost any question you would be asking about them. I would recommend Python, with libraries numpy, scipy, and Pandas. For certain kinds of analysis, you could also use the scikit-learn and statsmodels packages.
The easiest way to install all of these, is to download Anaconda, which contains all of these packages and makes installation really easy.
If you prefer not to program too much, you could also use PSPP, but the flexibility of Python is a big advantage.
Multiple regression is handled by all packages. I see that wiki indicates that R and PSPP handle Manova but the Python packages scikit learn and statsmodels don't. As usual, there is a Python package for it (spm1d). If it is a once-off analysis, use PSPP, otherwise, learn Python or R. It really helps in the long run.